In 1976, a still prevalent success story began: today‘s SEHO Systems GmbH started as SEHO Seitz & Hohnerlein GmbH, to drive rapid technology developments in the electronics industry. The enterprise emerged from a small wave soldering system provider into a global player offering customers complete solutions for soldering processes and automated production lines.

The company develops and manufactures machines for all fields of automated soldering processes. They started with the production of wave soldering systems. By 1985, the product range had been expanded to include reflow machines. They then revolutionized the production of electronic devices with the introduction of its first nitrogen wave soldering system in 1986. The ongoing miniaturization of components resulted in the development of a completely new soldering technology. In 1998, the company introduced the first selective soldering system with robotic handling. During recent years, SEHO successfully implemented its strategy of providing complete solutions and developed from a standard machine provider to one of the leading system suppliers with innovative automation technology for board handling and materials management. Today, the company offers its customers complete solutions for a large variety of manufacturing tasks.

In 2014, a new demonstration center was opened to illustrate these concepts to visitors. The company’s Technology Center provides customers a multitude of information in a very pleasant atmosphere. Being approximately 960 m2, there is enough space for demonstrating systems, meeting rooms, and a large event room for seminars and technology days.

The entire product range of soldering units can be found in the demo center. Naturally, all systems are ready for operation, executing all common soldering tasks for electronic assemblies. Various PCB variants of different sizes, weights, or placement types (single-sided, double-sided, multilayer etc.) are processed.

Odorless and clean premises

It is apparent that Technology Center’s visitors do not notice any odors, but every tinkerer knows the typical smell of molten solder. “There are strict legal regulations on air purification during system operation“, explains Hermann Liebler, Sales Area Manager. „Any soldering unit must not be operated without extraction and filtration.” Based on decades of activities with the company, among others in the area of process consulting, Hermann Liebler is considered as one of the soldering technology experts in Germany.

Depending on PCB type and mounted components, different solder alloys and fluxes are utilized. During a soldering process, large parts of the fluxes and smaller portions of the solder evaporate. Resulting aerosols and particles are released into the process air. In addition to spreading unpleasant odors, they can cause severe illnesses to the personnel. Aldehydes, occurring from substances containing colophony, are particularly dangerous having carcinogenic potential. Furthermore, gases evolving during the heating of conformal coatings, adhesives or carrier material must also be considered.

„The protection of machines and products should not be underestimated“, says Udo Kempf, Head of Application. Soldering fumes additionally contain adhesive aerosols, which may settle in the soldering systems and, in the worst case, contaminate products. This leads to increased maintenance efforts because system functionality can be reduced.

In order to guarantee required air purification, extraction and filtration systems are applied. But there are no piping or suction hoods on the ceiling. The reason is the building architecture with its wooden beam look was not to be destroyed by such installations, i.e. a centralized extraction solution was simply unsuitable. That is why the company decided to run an extraction and filtration device with each soldering system.

Flexible extraction solution for changing requirements

Currently, each of the seven stations in the demo center features an LRA 200 extraction and filtration unit from ULT. The vendor’s LRA system series was developed for soldering fume removal. All filtration systems are placed adjacent to the soldering machines and connected to the systems via piping. These extraction channels, installed by SEHO themselves, are designed to be run also with changing demonstration units. Hence, this is a flexible way to extract and filter soldering fume from the systems. Filtration rate of the exhaust air is extremely high (99.95 %), so that it can be fed back to the working area after the filtration process.

If an interested party decides to purchase a soldering unit, the company always recommends the acquisition of an air purification system – depending on the air pollutant volume they may vary in size and filtration performance. Partly, extraction devices are integrated into the soldering machine, if the customer’s production situation requires such a solution.

The LRA 200 extraction and filtration units are small devices for medium volumes of soldering fume. They are fully adequate in the Technology Center: „Our soldering systems are not running for several hours or even around the clock”, explains Udo Kempf. „Additionally, we use few fluxes, so that vapors hardly occur and the entire contaminant volume is relatively low.”

Since the extraction system purchase in 2015, it has not been necessary to exchange the filters, as they have not yet been saturated. On the one hand, this is due to the low quantities of soldering fume, and on the other by the special filtration concept within the extraction and filtration systems, which focuses on long-term filter lives at high filtration rates.

In contrast to selective soldering, however, there are further applications where an entire circuit board is wetted with flux, as in wave soldering processes. The emerging spray mists from alcohol based flux and other assembly evaporations may lead to explosive, highly flammable vapor/air mixtures. In this case, a larger extraction unit is utilized. It features an expanded metal prefilter to reduce the risk of explosions or fires.

The Academy – knowledge creates the future

In such a dynamic industry as electronics production, it is important to build and continuously improve know-how, to ensure production is at the highest quality level and simultaneously reduce manufacturing costs. The SEHO Academy lays the foundation for this. Well-educated and experienced trainers provide their knowledge in intensive seminars about the soldering processes, as well as the operation and maintenance of machines. The efficiency of the company’s training courses is based on a simple principle: to provide a perfect balance of theory and practical application.

In addition to process seminars and machine training courses, hand-soldering seminars are also available at the SEHO Academy. To this end, six workplaces have been set up, where a clean working environment plays a critical role. An LRA 300 filtration unit is utilized for soldering fume removal, providing a central extraction solution. Each workplace has extraction arms (Alsident 50), with respective capturing elements (suction tip), that are connected to the filtration system via piping. They efficiently remove all generated airborne pollutants. This way, seminar attendees, trainers, work materials, products, and workplaces are protected from the hazardous impact of soldering fumes and vapors.

A long-term relationship

The entire extraction and filtration technology applied at the company is provided by a single source. One reason is the long-term partnership between the soldering specialist and the company IVH Industrievertrieb Henning, ULT’s distribution partner for the south of Germany for nearly 20 years. Long before building the demonstration center and training rooms, soldering systems from SEHO have been run with ULT extraction and filtration systems at numerous customer sites. Udo Kempf considers the lasting relationship with IVH as an important reason in the purchase process of the filtration solutions for the demo center. „Why change a working relationship?” he asks with a smile. IVH assisted SEHO in an advisory capacity during the premises furnishing and, additionally, helped to make sure that “all things flew”, describes Udo Kempf further.

The extraction and filtration systems run smoothly and straightforwardly – and are nearly noiseless. „One of the ULT devices’ major advantages is their quiet operation”, says Udo Kempf. „Easy operation, high extraction and filtration performance; and one can hardly hear the systems running. That is fun air purification.”